Sozin Attack

With 6. Bc4 White places the king's bishop on the a2–g8 diagonal against a Black setup with pawns on d6 and e6. The move is also known as the Fischer–Sozin Attack, after Veniamin Sozin, who introduced it in the 1930s, and Bobby Fischer. Black's ...e6 already blunts the bishop, so White's main plan is to add pressure on e6 by advancing the f-pawn to f4 and f5. The bishop usually drops back to b3 to avoid ...d5 or ...Nc6-a5 tricks. White can castle kingside, or castle queenside with Qe2 and O-O-O, the Velimirović Attack. Black counters on the queenside and down the c-file.

The most common replies are 6...a6 and 6...Be7. After 6...a6 7. Bb3 b5 Black starts immediate queenside expansion, the Flank Variation. 6...Nc6 is the Leonhardt Variation. In that line 7. Be3 is the Main Line, and 7. Bb3 Be7 8. Be3 O-O 9. f4 is the Fischer Variation. Play is sharp and heavily analyzed. The engine rates the position as roughly balanced, and Black scores slightly better than White in online games.